1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to a microfluidic valve, and more particularly, to a microfluidic valve for controlling flow of a fluid through structures in a platform, a method of manufacturing the microfluidic valve, and a microfluidic device including the microfluidic valve.
2. Description of the Related Art
Devices that perform a biological or chemical reaction by manipulating a small volume of a fluid are referred to as microfluidic devices. A microfluidic device includes microfluidic structures disposed in a platform, wherein the platform can have various shapes such as a chip shape or a disc shape. The microfluidic structures include chambers that can hold a fluid, channels through which the fluid can flow, and valves that can control the flow of the fluid. Thus, microfluidic devices can be manufactured by various combinations of these elements.
A device manufactured to perform various steps of fluid treatment and manipulation including experiments of biological reactions by disposing microfluidic structures in a flat chip form is referred to as a lab-on-a chip. In order to transport a fluid in a microfluidic structure, a driving pressure is required. As the driving force, a capillary force or pressure generated by an additional pump is used. Recently, disc type microfluidic devices that perform a series of operations by having microfluidic structures disposed in a flat disc form and moving a fluid through the microfluidic structures using a centrifugal force have been disclosed. This type of device is referred to as a Lab compact disk (CD) or a Lab-on a disc.
In order to perform complicated processes in microfluidic devices such as a Lab CD or a Lab-on a disc, a plurality of microfluidic valves that are disposed at various position to control the flow of a fluid are required. Also, in order to mass produce the microfluidic devices, a method of efficiently manufacturing the microfluidic valves together with chambers and channels has been desired.
A method of controlling the flow of a fluid using a phase change material that is a solid state at room temperature and is melted at a high temperature has been proposed. A biochemical reaction substrate disclosed in Anal. Chem. Vol. 76, 2004, pp 1824-1831 includes a valve formed of paraffin wax and a heating element for melting the paraffin wax. However, the valve included in the above substrate requires a large amount of paraffin wax in order to close minute channels, and a large heating element must be included to melt the large amount of paraffin wax. Thus, it is difficult to miniaturize or integrate the biochemical reaction substrate. Also, a long heating time is required to melt the paraffin wax and it is difficult to precisely control the opening time of channels.